Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden for behavioral context. It clearly implies a read-only operation ('List'), which is useful but does not disclose potential failure modes, authentication requirements, or whether the response format might vary. It adds minimal value beyond the name and schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, concise sentence that front-loads the main action ('List') and provides the key details (what is listed, where it comes from, and the additional Node.js version). Every word earns its place with no redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the low complexity (one parameter, no output schema), the description adequately conveys what the tool returns (packages and Node.js version). It lacks explicit error conditions or edge cases, but for a simple listing tool this is sufficient. A slightly higher score would require more behavioral detail.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already fully describes the only parameter ('app') with a clear description ('App ID (UUID) or subdomain'). The tool description does not add further meaning or usage details for the parameter, so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('List') with a clear resource ('npm packages') and source ('from package.json'), and distinguishes itself from siblings like install_packages, remove_package, and search_packages by focusing on read-only inspection. It also mentions the included Node.js version, adding further specificity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies this is for viewing installed dependencies and the Node.js version, but it does not explicitly state when to use this tool over alternatives. It does not mention any exclusions or provide a 'use this instead of...' pointer, so guidance is only implicit.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.